In the end Silvia got her PID

[dyknicke]

Hi all,

I just finished another Silvia makeover. I added a CAL 9900 controller to my Silvia. It took some time but it looks nice I will borrow a calibrated temperature meter from work this weekend to do some serious measurements.

What temperature do you guys set your controller to aim at (my TC is attached under a screw at the top of the boiler)? I know it depend what blend you are using at the moment but then give me a temperature/blend figure.

/Niclas

[matts]

Currently have mine at 225F (sorry what's that in C?), TC in the same place as you.

Cheers
Matt

[simonp]

I'm running at 220F, but my thermocouple is mounted about half way down the boiler.

[Ian]

Niclas, you could leave the controller connected but temporarily reconnect the thermostat instead of having the SSR doing the switching. The controller will then show you the temperature range that the standard thermostat works under. That would give you a starting point for your particular machine/tc placement.


Ian

[dyknicke]

Ian, I tried that before I completed the installation and realised (as many others) that the original thermostat really sucks (if you want a stable temp without temp surfing). After the heater was turned off, a temperature raise of 10 degrees C took place. It is difficult to compare these figures with other people measurements since nearly all the java geeks are from the US and have a different heater (voltage).

Niclas

[quink]

Nice mod, how did you attach the pid to the side of the silvia? Its probably my monitor but I cant make it out.

[wlodek]

I just finished another Silvia makeover. I added a CAL 9900 controller to my Silvia. It took some time but it looks nice I will borrow a calibrated temperature meter from work this weekend to do some serious measurements.

Niclas, could you post some pictures of the internal (re)connections and also how you connected the controller box to the machine? I would like to avoid drilling Silvia (as it were of course).

I already have a nice little (DIN 1/16) 6100+ controller with dual display (actual and setpoint), an SSR, a project box, a pretty lit switch, only missing a thermocople - really looking for a bargain/free one, as I have been already pointed towards some normal sources in the UK by friendly souls on this forum - and some mounting bits: cables with decent temp. rating, connectors and perhaps a piece of nice pliable steel conduit (gooseneck style) with mounts.

I am thinking about mounting the SSR in the (metal) controller box, as I am a bit dubious about the 'naked' 240V connectors on the SSR only hidden behind the splash screen. I would then have 4 cables (2 for thermocouple, 2 for the heater instead of the SSR) to route, possibly 6 if I run the mains feed into the controller off the Syliva mains switch. There would be slightly less messing around in Silvia as well (as it were).

Any thoughts/experience on this last issue?

W.

[dyknicke]

Ok, I will post som pictures of the internals later on this week. I haven't made any modifications to Silvias case. Everything can be removed without any trace.

The controller box is "hanging" on the edge of the cup holder (a bent piece of metal attatched to the controller box) and attached to the side of Silvia with some velcro closing.

I tried to find a place inside Silvia to place the SSR but ended up placing it on the "standard place" behind the splash screen. The SSR I have needs some cooling so I mounted it as all the other PID-heads

/Niclas

[wlodek]

Thanks Niclas, no rush here, I'll appreciate that. I think (unless I get a really negative comments on this here) I'll put the SSR in the (aluminium) controller box, so it will get even more cooling than behind the splash-screen (quite a warm place by the look of it).

W.

[dyknicke]

If you do, don't forget to ground the box! (using a metal box)

[wlodek]

Good point, thanks.
W.

[matts]

I am thinking about mounting the SSR in the (metal) controller box, as I am a bit dubious about the 'naked' 240V connectors on the SSR only hidden behind the splash screen. I would then have 4 cables (2 for thermocouple, 2 for the heater instead of the SSR) to route, possibly 6 if I run the mains feed into the controller off the Syliva mains switch. There would be slightly less messing around in Silvia as well (as it were).

Did you see the pics here?
http://www.murphyslawonline.com/silvia/

No need to drill anything, all the cables can be fed in the bottom corner and through various spaces. I'm not sure the 'naked' thing is an issue, you'd be going some to get enough water splashed up there in sufficient quantities to make the whole case live IMHO, and you can get plastic covers that fit over the SSR covering the connections if you want. I'd also probably trust the grounding already built into Silvia more than your wee alu box if there was a disastrous frying episode, but maybe that's just me

Cheers
Matt

[wlodek]

Did you see the pics here?
http://www.murphyslawonline.com/silvia/

Yes, I have, this is an excellent tutorial step-through. I may write a 'tuning' addendum eventually.

[...] you can get plastic covers that fit over the SSR covering the connections if you want. I'd also probably trust the grounding already built into Silvia more than your wee alu box if there was a disastrous frying episode, but maybe that's just me

Yes, plastic covers are an option. But the alu box is quite a solid die-cast one (yes, it's probably you - not trusting other people's alu boxes, and right before Christmas too) and I was planning decent earthing for it anyway.
Having the SSR inside Silvia has the advantage of only routing low power cables. I'll think about this one.

Thanks,
W.

[dyknicke]

Hi all!

Before I start, I will post some pictures later this weekend

As I told you before, I borrowed a calibrated temperature meter this weekend. I rushed home from work and started immediately. I only measured the highest temp since when the shot is going, the controller is out of the game. Previous measurments done by others proved that Silvia keeps the temperature during the shot is a good way.

I put the probe in the filter basket a la Schomer, but without the coffee...

Ok, here we go!

Setting (C):____Max Measured Temp (C):
102,8___________93,7
102_____________92,9
100_____________92,3
99______________91,8
98______________91,2
96,8____________90,6
95______________88,9
103_____________92,3
103_____________92,4
104,1___________94,3
104_____________94,9
104_____________95,3

While doing the tests above I didn't remove the porta filter. My goal was to find the water temperature coming out from the machine.

In the next series of measurements I removed the porta filter between each test to simulate the "grind and tamp" procedure before I put it back. This is a good way to see if a "cold" filter affects the outcoming water temperature.

Setting (C):____Max Measured (C):
103,5___________93,7
103,5___________94
103,7___________93,3
103,7___________93,9
104,5___________94,9
104,5___________95,4
105_____________95,4
105_____________95,6
103,9___________94,6
104_____________94,8
104_____________94,3


/Niclas

[wlodek]

This is interesting. Did you take these measurements at regular intervals? Roughly what were the intervals?

If you look at the plot of your measurements here you will see a nice hystheresis loop. It looks like you may have been measuring in a sequence, not waiting for the setpoint to be reached. Is this possible? If you did (you can check this on the PID display) then it means that the desired boiler temp. was reached, but there is an additional mass (the group?) that needs to be heated in order for water temperature to be controlled. Would this point to a need of temperature measurement elsewhere? Additional sensor and more dimensions to the control problem?

W.